What is the standard scan rate for HF weather facsimile reception from shore stations in the 3 MHz to 23 MHz range?

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Multiple Choice

What is the standard scan rate for HF weather facsimile reception from shore stations in the 3 MHz to 23 MHz range?

The key idea is how quickly a weather facsimile image is built line by line. For HF weather fax transmissions from shore stations in the 3–23 MHz range, the standard scan rate is 120 lines per minute. This means about two image lines are produced each second, a pace chosen to balance readable image quality with the typical page size and the way weather fax data is encoded and transmitted. At this speed, a full page can be received in a practical amount of time and with reliable decoding across standard receivers. Rates that are much slower or faster would not match the established timing used for these transmissions, which is why 120 lines per minute is the correct standard.

The key idea is how quickly a weather facsimile image is built line by line. For HF weather fax transmissions from shore stations in the 3–23 MHz range, the standard scan rate is 120 lines per minute. This means about two image lines are produced each second, a pace chosen to balance readable image quality with the typical page size and the way weather fax data is encoded and transmitted. At this speed, a full page can be received in a practical amount of time and with reliable decoding across standard receivers. Rates that are much slower or faster would not match the established timing used for these transmissions, which is why 120 lines per minute is the correct standard.

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